Traction device.



M. E. SCHMIDT. TRACTION DEVICE.

APPLICATION FILED 0m. 28, 1908.

Patented Nov 9, 1909.

I feuenzor;

' (I! 02%MJZZZ Z}: afl r eyi MAX E. SCHMIDT, 0F CONVENT, NEW JERSEY.

TRACTION" nEvIcE Specification of Letters Patent.

Patented N 0v. 9, 1909.

Application filed O0tobBij28, 1 908. SeriaLNo. 459,852.

To all whom it may concem: I

Be it known that L'MAX E. SCHMVIDQQL. citizen of the United States, and a resident of Convent, Morris county, State of New Jersey, have invented pertain new and useful Improvements infTraction Devices, of which the following is a specification, reference being had to the accompanying drawings, in which Figure 1 is a diagrammatic top view of arts of an endless carrier embodying one orm of my invention; Fig. 2 is a side view of parts on enlarged scale; and Fig. 3 a vertical section on the line 3--3 of Fig. 2

My present invention relates particularly to that class of carriers, described in U. S. Letters Patent No. 747,090 granted to me and G. A. Mayland December 15th, 190?), which'consists of a series of unitary members or carriers sequentially coupled "to constitute a substantially continuous movingplatform propelled by the rotation of a series of wheels disposed beneath the same and upon the treads or peripheries of which the said carriers are supported upon rails secured to the. latter, the treads of which rails are downwardly presented and dis posed, so as to bear upon and coact with the-- treads of said wheels in such "manner that the rotation of the latter causes the said rails, with their connected carriers, to advance with approximately the same speed of movement as the peripheries'of said wheels. Since my said patent was granted, my researches, have disclosed that it is important for the full development and successful application of the required tractive force to the runnin gear of an endless conveyer, that substantial y all of its supporting wheels should be positively rotated. If, for instance, the driving Wheels are placed in the running'gear a given distance apart, each one of said wheels, or groups of wheels, must develop suflicient tractive force to move a length of the conveyor of the given distance, to'accomplish which various devices have been hitherto resorted to, added weights for instance to increase. friction, and thus traction, between the parts contacting and moving relatively to each other.

The object of my present invention is to provide means whereby the total propulsive orce required to move the conveyor may be successfully and uniformly distributed at a plurality of points, the number of which is practically indefinite, and there so imparted to increase the aggregate tractive power developed and thereby insure at all times steady and equal progression imthe running gear of the endless conveyer without resort to additional weights or other devices.

It will be ,noted that in carriers of the i moving platform type referred to, the

unitary members or carriers constituting such platform are each, taken separately, of relatively moderate weight as compared to the aggregate weight of the entire platform taken as a whole. Consequently very considerable power is required to propel the entire platform, as compared to one of its units. Such power is necessarily the resultant of the amount of propulsive force applied to rotate the smooth faced driving wheels and the amount of pressure or tractive force with which the downwardly presented treads of the rails of the unitary carriers bearagainst said driving wheels. In

other words, the propulsion of the platform depends upon the weight thereby brought to bear upon the propelling wheels, z. e. upon the aggregate adhesion of said smooth faced propelling wheels against the treads of its said rails.

In the type of device referred to, the aggregate combined weight of all the unitary carriers cannot be'concentrated at any given point, or points, and the propulsive force to move the platform can therefore not be applied at such point, or points, in conjunction with the tractive force which would develop from the adhesion obtained from such a concentration of weight. In previous constructions this has caused diificulties; and my present invention comprises an expedient whereby these are overcome. By my present device it is possible to produce effects similar to those resulting from such concen tration as aforesaid. This I accomplish b multiplying the number of driving whee s actuated by one, and the same, motor and disposing them so as to support, not as hereinstead of one. For example, assume that, as in prevlous constructions, the pairs of wheels actuated positively by motors are one hundred feet apart, the platform being intermediately-supported on intervening ire of idler wheels say ten feet apart and he unitary carriers being each ten feet long. It is apparent that in such case the tractive force brought to bear upon each pair of wheels, while positively actuated by a motor ofgiven denomination, will be such as may be developed from the weight. of the single unitary carrier then tracking with saidIpair of driving wheels. If now, as per my said invention, say four pairs of said idler wheels, two on each side of said actuating pair, be

geared with the latter so that the entire. group are also rotated positively by said motor then there will be applied to the propulsive force of the latter, less an unimportant loss through friction, the combined weight, adhesion and consequent tractive force of five, instead of one of said unitary carriers. I am thus enabled to multiply tractive force, without materially increasing power. I accomplish this object by the devices hereinafter described which comprise, broadly speaking, means for imparting from a common source of power to a series of supporting wheels, not only positive but also synchronous rotation.

Referring now to the drawings, Z, Z, are pillars or stationary supports in which are journaled rotatable shafts is, carrying fixed thereto wheels 11;, which support and propel the tracksb', secured to eachunitary carrier p, ofthe series constituting the endless carrier or moving platform. These tracks, I), it

will be observed, have their treads downwardly presented and bearing upon the peripheries of the wheels w. Each of said unitary members is coupled to the preceding and followingone in any convenient manner as preferably by coupling pins e, engaging with link d, secured to each preceding unitary carrier. Means are provided to insure against transverse displacement, as for instance downwardly extending projections n, preferably extensions of pin e, which travel within continuous guide rails 9 supported stationarily by braces h, friction being preferably relieved by friction rollers 7, or other means shown in said patent may be employed.

7' represents diagrammatically means for applying power to rotate shaft is, in thisinstance an electric motor. It will be obvious that as shaft is is rotated the tractive force thereby imparted to the supporting wheels 'w will propel in turn each unitary carrier .in the direction of rotation, and

that suc carrier will also be supported as against transverse displacement by the downwardly extending projections f engagingIin the endless stationary tracks 9.

one of theforegoingpar-ts referred to by letter'constitute any part of my present invention unless as elements in combination, they being substantially the same as those heretofore described in my said Letters Paten't No. 747,090.

My present invention comprises for the purposes aforesaid the application to the said devices of means for transmitting rotation synchronously from each power shaft k to other shafts k and their appurtenant supporting wheels '20 and to this end, and

boring shafts. An endless chain B is operatively connected with two of the sprocket wheels, in alinement, of each adjacent pair of shafts. By their aforesaid connection each of the shafts is caused to rotate positively and at the same time synchronously with those shafts to which power is directly applied as aforesaid and the'entire series of parallelly disposed shafts is likewise rotated so that each member of the running gear thus connected transmits and delivers to the load, at the various points of contact, tractive force simultaneously and in substantially equal degree.

I have further devised means for continuing the aforesaid connecting of the shafts to embrace portions of the course separated by curves. This with special reference to the type of conveyer described in said U. S. Patent 7 47,090. As an illustration of one of such means the shafts J and K Fig. 1) are shown extended and operative y connected by the gears G G. It is preferable that such extended or transmission shafts, as they may be termed, should each be positively actuated by a motor 7' as shown. By this means the quality of tractive force and synchronism of rotation is mechanically secured between series of shafts separated by a curve in the course of the carrier. It will be understood that by suitably beveled gears, or other obvious mechanical means, the transmission 'of uniformity and synchronism of rotation may be transmitted at any desired angle instead of in parallelism as shown between the shafts K, K, Fig. l, merely for illustration; also that means other than sprocket wheels and chains specifically may be employed to secure synchronism of rotation, as for instance suitable trains of gears, etc.

' In Fig. 1 the entire series of unitary carriers constitutin the endless platform is not shown in or er that sub-disposed members may be more clearly erceived. It will be understood however t at in operation, the unitary carriers p are sutiicient in number to produce an endless chain thereof coverin the entire system of supporting wheels W, 5V etc.

[Referring now more speclally to the ceases curved portions or said running gear the shafts K of Fig. 1 represent idler-shafts carryin cept that they are, as stated, idlers- By this means, in combination with the devices hereinbefore described, the endless. carrier and. its unitary members of the type ofconveyers described in said Patent No. 747,090are insured uniformity sion when progressing curvedly It will be understood that the novel means which, I have described for increasing trac-' tion by as aforesaid insuring uniformity and synchronism of rotation in aplurality of shafts comprised in a power transmission than that of the device is applicable to other tractiondevices particular endless carrier above described. f y

I am aware that means have been employed to synchronize the rotations of a plurality of shafts provided with, gear wheels engaging rack links to drive endless chains. 1- refer to devices sometimes desi ated traveling Stairways. In these evices said chains are connected with a plurality of trucks which carry the steps composing the stairway. Said trucksaresupportedon idler wheels tracking with stationary rails,

none of said wheels being drivers. Such devices are, therefore, not traction devlces 1n the sense of nnne, and constitute no part of my invention, being distinguishable therefrom in that, among other things, the former are propelled only by direct engagement of said gear wheels with said rack links, and the weightof the runnin ear of the said traveling Stairways including their said idler wheels, is at all times only a dead load upon the propulsive force employed, instead of, as per my invention, utilized in part to coact therewith in promoting pro ulsion, whereby I am enabled to dispense with the said previously requiredidler wheels W The last mentioned s a-fts and wheels are supported iden-'- tically as the wheels and shafts w andk. ex

and steadiness of progresshafts, and, interposed between 'saidjparallelly disposed shafts ra with wheels upon which said treads bear for supporti-and propulsion of. said platform, means for im arting rotation to some of said shafts, and

with underneath rails having downwardly presented treads, a plurality 'of mutually parallel shafts rotatable in stationary bear-' mgsand rovided with wheels upon which said trea s bear to progress straightlyf means for imparting rotation to some 0 .said mutually parallel shafts, means for transmitting rotation therefrom synchronously toi'others of said mutually parallel groups of ially disposed shafts provided with idler wheels upon which said treads bear to progress curvedly. V

3. A traction device comprising an endless latform. composed of a plurality of coup ed-together unitary carriers provided with underneath rails having downwardly presented treads, a plurality of shafts rota- ,table in stationary bearings and provided with wheelsupon whichsaid treads bear for support and propulsion of said platform, means for imparting rotation to some of said shafts, sprocket wheels in mutual alinement and rotated by consecutive pairs of said shafts, and endless chains operatively engagingwith said sprocket wheels to transmit rotation synchronously from one to another of said shafts.

4. A traction device com rising a plural ity ofindependent, couple -together, unitary carriers, supporting rails, a plurality of smooth faced bearing wheels tracking with said rails to support each said carrier respectivelyf a motor, means to transmit power from said motor directly to some of said wheels to positively rotate them while supporting one of said carriers, and means means for transmitting rotation therefrom to others ofsaid shafts.

' .2. A traction device comprising an endless platform vcomposed of a plurality of coupled-together unitary. carriers provided totransmit power from said inotor to positively rotate others of said wheels while su porting others of said carriers, substantial y as and for the urposes described, whereby traction oplposed to said motoris increased,

substantia y as and for .the purposes described.

MAX E. SCHMIDT.

Witnesses: V

PHILIP C. PEoK, G. G. MEASURES. 

